How to play Encrypted video File In Adobe Air Video Player

Hello Friends

                      I am making A custom video player in adobe air.in which video path comes from xml stored in ur system.but that xml contains the encrypted path of all video file.I have to make a video player in adobe air which First Decrypt that enncryped file to get original FLV files and then play them.I mean All the decryption logic is implemented at our side(Action Scripting).So can And Any body please guide me that is there any Flash/Flex Inbuilt Api for Decryption.If Yes Then Please Guide me,Its very Intersting and new task.I am Attaching the pictorial view for that.

Thanks And Regards

    Vineet osho